Low-Dose Ketamine Infusion for Managing Acute Pain

A Systematic Review and Meta-analysis of Ketamine as an Alternative to Opioids for Acute Pain in the Emergency Department

BACKGROUND

Opioids are commonly prescribed in the emergency department (ED) for the treatment of acute pain. Analgesic alternatives are being explored in response to an epidemic of opioid misuse. Low-dose ketamine (LDK) is one opioid alternative for the treatment of acute pain in the ED.

OBJECTIVES

This systematic review and meta-analysis sought to quantify whether LDK is an effective and safe opioid alternative for acute pain reduction in adults in the ED setting. (PROSPERO Registration Number CRD42017065303).

METHODS

This was a systematic review of randomized controlled trials comparing intravenous opioids to LDK for relief of acute pain in the ED. Studies where the control group initially received opioids prior to ketamine were excluded. A research librarian designed the electronic search strategy. Changes in visual analog scale or numeric rating scale pain scales were analyzed to determine the relative effects of LDK and opioids in the treatment of acute pain.

RESULTS

Three studies met the criteria for inclusion in this meta-analysis. Compared to pain scale reduction with morphine, ketamine was not inferior (relative reduction = 0.42, 95% confidence interval = -0.70 to 1.54). No severe adverse events were reported in any study, but higher rates of nonsevere adverse events were observed with ketamine.

CONCLUSIONS

Ketamine is noninferior to morphine for the control of acute pain, indicating that ketamine can be considered as an alternative to opioids for ED short-term pain control.

The Effects of Low-Dose Ketamine on Acute Pain in an Emergency Setting: A Systematic Review and Meta-Analysis

OBJECTIVES

Currently ketamine is not used often as an analgesic in the emergency department (ED). Nonetheless, it can increase the efficiency of opioids and decrease their side effects. The purpose of this systematic review and meta-analysis was to evaluate whether low-dose ketamine in the ED provides better analgesia with fewer adverse effects.

METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched by two reviewers independently (last search performed on January 2016). Data were also extracted independently.

RESULTS

A total of 6 trials involving 438 patients were included in the current analysis. Our subgroup analysis of pain reduction indicates that the favorable effects of ketamine were similar or superior to those of placebo or opioids, although these effects were heterogeneous. However, low-dose ketamine was associated with a higher risk of neurological (relative risk [RR] = 2.17, 95% confidence interval [CI] = 1.37-3.42, P < 0.001) and psychological events (RR = 13.86, 95% CI = 4.85-39.58, P < 0.001). In contrast, the opioid group had a higher risk of major cardiopulmonary events (RR = 0.22, 95% CI = 0.05-1.01, P = 0.05).

CONCLUSIONS

The efficiency of ketamine varies depending on the pain site, but low-dose ketamine may be a key agent for pain control in the ED, as it has no side effects. It may also help to reduce the side effects of opioids.